1. Technical Field
The present disclosure generally relates to a bump structure, and more particularly, to a micro-bump structure having self-aligning functions.
2. Description of Related Art
During the applications of fine-pitch micro-bump packages, due to (1) the poor alignment capability of the apparatus, (2) low uniformity of the bump, (3) insufficient tin amount in the bump or (4) inferior soldering properties of the bump, misalignment or alignment shifting often occurs, which seriously deteriorates the bonding ability of the bump.
Because the fine-pitch micro-bumps have much less tin amount than the flip-chip bumps, it is unlikely for the shifted bumps (or connections) to move back to the predetermined positions following the capillary effects of the solders, even going through multiple times of reflow treatments.
Practically, the industry is keen to see whether further solutions can be provided to increase the alignment accuracy or to solve the alignment shifting problems, so that the bonding strength and the reliability of the micro-connections are improved.